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i2c: stm32f7: add PM_SLEEP suspend/resume support

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Backup/restore I2C registers as part of the suspend/resume
handlers. The device is marked as suspended to ensure that
transfers are rejected during the suspended period.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Alain Volmat <alain.volmat@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Alain Volmat 2020-01-06 14:28:32 +01:00 committed by Wolfram Sang
parent 9253975bcb
commit ea6dd25dee
1 changed files with 113 additions and 4 deletions
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117
drivers/i2c/busses/i2c-stm32f7.c
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@ -168,6 +168,24 @@
#define STM32F7_AUTOSUSPEND_DELAY (HZ / 100)
/**
* struct stm32f7_i2c_regs - i2c f7 registers backup
* @cr1: Control register 1
* @cr2: Control register 2
* @oar1: Own address 1 register
* @oar2: Own address 2 register
* @pecr: PEC register
* @tmgr: Timing register
*/
struct stm32f7_i2c_regs {
u32 cr1;
u32 cr2;
u32 oar1;
u32 oar2;
u32 pecr;
u32 tmgr;
};
/**
* struct stm32f7_i2c_spec - private i2c specification timing
* @rate: I2C bus speed (Hz)
@ -276,6 +294,7 @@ struct stm32f7_i2c_msg {
* @timing: I2C computed timings
* @slave: list of slave devices registered on the I2C bus
* @slave_running: slave device currently used
* @backup_regs: backup of i2c controller registers (for suspend/resume)
* @slave_dir: transfer direction for the current slave device
* @master_mode: boolean to know in which mode the I2C is running (master or
* slave)
@ -298,6 +317,7 @@ struct stm32f7_i2c_dev {
struct stm32f7_i2c_timings timing;
struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
struct i2c_client *slave_running;
struct stm32f7_i2c_regs backup_regs;
u32 slave_dir;
bool master_mode;
struct stm32_i2c_dma *dma;
@ -2027,8 +2047,7 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
return 0;
}
#ifdef CONFIG_PM
static int stm32f7_i2c_runtime_suspend(struct device *dev)
static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
@ -2038,7 +2057,7 @@ static int stm32f7_i2c_runtime_suspend(struct device *dev)
return 0;
}
static int stm32f7_i2c_runtime_resume(struct device *dev)
static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
@ -2053,11 +2072,101 @@ static int stm32f7_i2c_runtime_resume(struct device *dev)
return 0;
}
#endif
static int __maybe_unused
stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
{
int ret;
struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0)
return ret;
backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
backup_regs->pecr = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
pm_runtime_put_sync(i2c_dev->dev);
return ret;
}
static int __maybe_unused
stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
{
u32 cr1;
int ret;
struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0)
return ret;
cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
if (cr1 & STM32F7_I2C_CR1_PE)
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR);
writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE,
i2c_dev->base + STM32F7_I2C_CR1);
if (backup_regs->cr1 & STM32F7_I2C_CR1_PE)
stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
writel_relaxed(backup_regs->pecr, i2c_dev->base + STM32F7_I2C_PECR);
pm_runtime_put_sync(i2c_dev->dev);
return ret;
}
static int __maybe_unused stm32f7_i2c_suspend(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
i2c_mark_adapter_suspended(&i2c_dev->adap);
ret = stm32f7_i2c_regs_backup(i2c_dev);
if (ret < 0) {
i2c_mark_adapter_resumed(&i2c_dev->adap);
return ret;
}
pinctrl_pm_select_sleep_state(dev);
pm_runtime_force_suspend(dev);
return 0;
}
static int __maybe_unused stm32f7_i2c_resume(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_resume(dev);
if (ret < 0)
return ret;
pinctrl_pm_select_default_state(dev);
ret = stm32f7_i2c_regs_restore(i2c_dev);
if (ret < 0)
return ret;
i2c_mark_adapter_resumed(&i2c_dev->adap);
return 0;
}
static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
stm32f7_i2c_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume)
};
static const struct of_device_id stm32f7_i2c_match[] = {